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. 2000 Jul;182(13):3867-9.
doi: 10.1128/JB.182.13.3867-3869.2000.

Decoupling of genome size and sequence divergence in a symbiotic bacterium

J J Wernegreen  1 , H Ochman, I B Jones, N A Moran
Affiliations

Decoupling of genome size and sequence divergence in a symbiotic bacterium

J J Wernegreen et al. J Bacteriol. 2000 Jul.

Abstract

In contrast to genome size variation in most bacterial taxa, the small genome size of Buchnera sp. was shown to be highly conserved across genetically diverse isolates (630 to 643 kb). This exceptional size conservation may reflect the inability of this obligate mutualist to acquire foreign DNA and reduced selection for genetic novelty within a static intracellular environment.

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Figures

FIG. 1
FIG. 1
Conservation of genomes sizes in Buchnera. Buchnera chromosomes digested with rare-cutting restriction enzymes were run on pulsed field gels to estimate genome sizes. Lanes are labeled by the abbreviation for the host name (Ap, A. pisum; Rp, R. padi; Sg, S. graminum; Mr, M. rhois). Note that I-CeuI cuts once and linearizes the Buchnera chromosome. With this enzyme, genomes sizes of Buchnera from S. graminum, R. padi, and A. pisum are indistinguishable. The finding of a slightly smaller genome size of Buchnera from M. rhois is supported by several independent enzyme digests.
FIG. 2
FIG. 2
Relationships and genome sizes of Buchnera taxa. Host abbreviations are as given in Fig. 1. Divergence times are based on the aphid fossil record (8, 17).
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References

    1. Andersson J O, Andersson S G E. Genome degradation is an ongoing process in Rickettsia. Mol Biol Evol. 1999;16:1178–1191. - PubMed
    1. Andersson S G E, Kurland C G. Reductive evolution of resident genomes. Trends Microbiol. 1998;6:263–268. - PubMed
    1. Baumann P, Moran N A, Baumann L. The evolution and genetics of aphid endosymbionts. Bioscience. 1997;47:12–20.
    1. Bergthorsson U, Ochman H. Distribution of chromosome length variation in natural isolates of Escherichia coli. Mol Biol Evol. 1998;15:6–16. - PubMed
    1. Carlson C R, Kolsto A B. A small (2.4 Mb) Bacillus cereus chromosome corresponds to a conserved region of a larger (5.3 Mb) Bacillus cereus chromosome. Mol Microbiol. 1994;13:161–169. - PubMed

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